Oropharyngotonsillitis associated with nonprimary Epstein-Barr virus infection.

OBJECTIVE: To identify distinct clinical features of pharyngotonsillitis or oropharyngitis associated with Epstein-Barr virus (EBV) infection from herpes simplex virus infection.
DESIGN: Clinical studies by case exploration.
SETTING: Institutional practice at a university hospital. PATIENTS: Thirty-three patients with pharyngotonsillitis and 4 patients with oropharyngitis of nonbacterial infection underwent biopsy of pharyngotonsillar lesions. MAIN OUTCOME MEASURE: The specimens were examined by histopathology, immunohistochemistry, in situ hybridization, and polymerase chain reaction. In addition to serological testing and routine laboratory data, photographic oropharyngeal findings were collected for clinical evaluation.
RESULTS: In situ hybridization to detect EBV-encoded small nuclear RNA-1 and -2 disclosed 8 cases of pharyngotonsillitis and 4 cases of oropharyngitis associated with EBV infection. Immunohistochemical analysis identified 5 cases of pharyngotonsillitis associated with herpes simplex virus infection. Serological examination showed that, among 12 cases positive by in situ hybridization, 3 cases were primary infection with infectious mononucleosis and 9 were nonprimary infection. The staining pattern of in situ hybridization was different, ie, a linear pattern in cases of nonprimary infection and a scattered pattern in cases of primary infection. The clinical manifestations of EBV pharyngotonsillitis were distinct from those of herpes simplex virus pharyngotonsillitis and were characteristic irrespective of infectious status, while those of EBV oropharyngitis were more variable.
CONCLUSIONS: Epstein-Barr virus-associated pharyngotonsillitis was demonstrated in patients with nonprimary infection unaccompanied by infectious mononucleosis. Epstein-Barr virus should be considered a potential causative agent of oropharyngotonsillitis even in absence of infectious mononucleosis, especially in a young adult.